Gene Expression

i-6c08b5abbb70dde83bbd565a854b2f3c-evolutionwhatfossils.jpgEvolution: What the Fossils Say and Why It Matters is an expansive new book authored by vertebrate paleontologist Donald Prothero and lushly illustrated by Carl Buell. The quality of the plates and illustrations, the binding as well as the texture of the pages, screams out “Coffee Table Book.” That’s not an insult, but it just reinforces that this isn’t a monograph aimed at specialists, rather, it is in large part a manifesto aimed toward the general public. And its high production quality testifies to the fact that it wants to be taken seriously by marrying style with substance.

Though the subtitle places the emphasis on fossils, Prothero covers a lot of ground early on in the book which examines evolution from various angles outside of his core field of expertise. There is a quick overview of the ideas of evolution before Charles Darwin, as well as the necessary geological context which made an evolutionary model of biology plausible. Biogeography, Mendelian genetics and molecular biology are all brought into the discussion and shown to converge upon the validity of evolutionary theory and its assumptions of common descent with modification. Additionally, the book also tackles the topic of abiogenesis, since it often gets thrown in with the arguments about the validity of evolutionary theory by Creationists and other assorted skeptics. The number of topics which the author addresses before moving onto the paleontological meat of the book is rather mind-boggling, and the economy of the prose is impressive.

But this is actually one of the major issues, Donald Prothero is a paleontologist so some material delves into areas which are well outside of his specialty. A few of the characterizations of genetic terms I would quibble with, while there is no doubt that the author, as a paleontologist, tends to believe that evolutionary geneticists who emphasize the role of microevolutionary processes in shaping the tree of life overplay their hand. The relatively positive evaluation of Richard Goldschmidt’s ideas as well as the general sense that Evo-Devo supersedes much of the Neo-Darwinian Synthesis is in my opinion somewhat disputable. Though there is positive reference to Richard Dawkins’ The Ancestor’s Tale the author clearly has his sympathies in the camp of Stephen Jay Gould, which is reasonable considering his training as a paleontologist in the same department.

Evolution: What the Fossils Say and Why It Matters is definitely a popular book aimed at those who want a bird’s-eye view of this field from the vantage point of a paleontologist. If you want the geneticist’s take, I highly recommend John Maynard Smith’s The Theory of Evolution. After the whirlwind tour of all the different subjects which contribute to our understanding of evolution the book takes a deeper look at what paleontology teaches us. I don’t really know this area any better than a lay person, so from that viewpoint I have to say that I enjoyed it a great deal. Creationists regularly say that the examples of fossils which are transitions are now out-dated or have been proven false, and I assumed that they were lying or misrepresenting somehow, but now I know exactly what they are lying about! I was happily surprised at the relative depth and breadth of the fossil record today and the enormous sample space of transitional forms which flesh out the tree of life. Prothero takes an explicitly homocentric view, surveying the various branches of the evolutionary tree and converging upon our own species. He emphasizes repeatedly that the fossils imply a bushy phylogeny as opposed to a smoothly ascending ladder, which is consistent with the modern understanding of evolution as an undirected process which aims toward the best short-term solution to any given problem as opposed to some perfect design. There is an in depth exposition of how cladistics revolutionized systematics and taxonomy; a story which the author tells from his own vantage point as an insider during the critical periods of controversy. Not only did the cladistic revolution sweep over paleontology, it has also served as the philosophical underpinning for models of molecular evolution and the field of phylogenetics. There are ample specific expositions of the natural history of the various branches of the tree of life to flesh out our understanding within the context of the broader cladistic model of relationships. If the goal was to force the reader to think systematically through appealing to specific examples, from the emergence of whales to our own genus, I think that Evolution: What the Fossils Say and Why It Matters hits the bull’s-eye.

I read this book with its target audience in mind, those sincerely interested in evolution but with little biological training or education. The specific focus on fossils does I think give a somewhat skewed perspective, but if one keeps that it mind then there is no great issue here, and as I said I read this specifically to get a bones’-eye-view, so to speak. Nevertheless, I do think on occasion that the focus on Creationists and their misrepresentations of the fossil data does get to be a bit much. In particular much of the book is written as a rebuttal to the Creationist debater Duane Gish, author of Evolution? The Fossils say No!. Gish and Young Earth Creationism looms large in the narrative. Prothero does a good job of rebutting the inanity of most of their arguments, and I particularly appreciated the geological perspective that he brought as a paleontologist. The point that modern oil exploration is contingent upon a conventional understanding of the earth’s history is well taken, and an angle I hadn’t considered before. That being said, Young Earth Creationism is such a retarded foil that I sometimes feel as if it drags the argument down, and I am not really convinced that any followers of that movement will be purchasing Prothero’s book. It is a good reference for rebutting all their arguments, but you can find that at Talk Origins. I would have rather that the narrative focus more on the scientific detail of paleontology and natural history, which I found fascinating, rather than the mendacious obfuscations of Creationist debaters. It is also notable that Prothero spends little time on tacking Intelligent Design. In part this is likely because that Neo-Creationist movement spends less time asserting blatant paleontological falsehoods, and its argument is more cleverly negative so that refutation is not the order of the day. But it is a movement which is gaining currency with more educated Creationists, so it seems that a more in depth rebuttal of their arguments would have been a better use of space than the repetitive assault on Duane Gish and his fellow travelers.

But in the end I would say that Evolution: What the Fossils Say and Why It Matters is a page turner. There are specific objections I have to the treatment of the history of evolutionary genetics or the weight that the author puts on different viewpoints within the academy in regards to specific evolutionary dynamics, but these do not detract from the meat of the book. Though perhaps not written with the fluidity of Richard Dawkins’ work the exposition of what we know about vertebrate paleontology was both accessible and dense, not a mean accomplishment. Prothero was also careful to frame the descriptive natural history within the context of overall evolutionary dynamics and an understanding of these processes within a cladistic framework, which is the orthodox position within systematics today. For those who are well versed in other domains of evolutionary science the narrative integrates the paleontology with other areas through its emphasis upon general processes and frameworks. Paleontology is not just descriptive natural history, rather, it is an avenue of exploration which is concerned with the same broad questions as evolutionary genetics. The prose is lively enough that a lay person won’t feel that they’re being bogged down in technical jargon, and the plates and illustrations allow one to anchor the text with a visual representation that is memorable. The glossy production value also means that this is a book that anyone would be comfortable with placing on a table in the living room for casual perusal. It bears greatest fruit when read as a whole and within the framework of the theories and models of evolutionary biology, but the later descriptive chapters are of interest in and of themselves and can be consumed a la carte. For those who are already steeped in evolutionary biology but are lacking in much knowledge of paleontology, Evolution: What the Fossils Say and Why It Matters serves as a good point of entry. Each chapter has a large bibliography that one can use as a guide to further reading. And for the lay person Donald Prothero has managed to balance entertainment and enlightenment to an admirable degree, this is a solid introduction to evolutionary science with the caveat that it offers the paleontologist’s take.

Comments

  1. #1 Toni Petrina
    November 26, 2007

    Thanks, I am definetly interested in buying that book. Can I ask you a favor? Could you in some of your future posts talk about evo-devo? I find wikipedia entry rather lacking in details and I would like to hear more from someone whose area of expertise is directly affected by it.

    Thanks

  2. #2 razib
    November 26, 2007

    pz is evo-devo, ask him to post more science :-)